Danish here: This isn’t exactly a foreign concept. All of my project exams in University had a written part (ranging from 50-150 pages), sometimes a technical part, and then an oral part where we defended the report. That’s one per semester.

Defending an essay would likely not take more than 15min, 3-4 hours was enough to probe a group of 7 to figure out who should get what grade based on contribution (or lack thereof if they just rode the other’s coattails). 5min to present the essay with a short summary, 5min for questions to probe the student, and 5 minutes for buffer.

I could even see this be used as a combined written/oral exam where you get a grade for both in a language class. If the essay is shit but your oral articulation in the foreign language is excellent then you could get top grade orally while failing on the written exam part. That means no actual loss of time.

The hard part is that most grades in our version of high school (gymnasium) are based on the teacher’s observations of your abilities in class. It is only some classes that are randomly selected for a end-of-year exam to save time. This idea about defending an essay wouldn’t work in the rest of the classes.